[Prev][Next][Index][Thread]
Re: (meteorobs) Sprite sighting
Hi Pete,
Was the association of the meteor and the sprite absolutely clear cut?
Unless the camera was pointing overhead, the meteor would be in quite a
different geographical region from the thunderhead as the heights were
probably 80+km and 5km respectively. Was the motion of the sprite
consistent with the orientation of the Leonid in three dimensions?
[off topic]
The lower parts of a thunderstorm are negatively charged, whereas the
upper parts are positive if I remember the (simplified) standard model.
The expression "a bolt from the blue" might refer to the occasional
positive lightning stroke that arcs from the top of the thunderhead often
through a clear sky and strikes the ground at some distance from the
storm. These flashes are usually more powerful than the standard
negative flash, are somewhat less common and often catch people unawares,
resulted in a number of deaths.
Robert H. McNaught
rmn@aaocbn.aaodot gov.au
On Fri, 25 Jun 1999, Gural, Peter S. wrote:
> Peter Bennett wrote:
>
> As I was watching, I saw a small fireball meteorite go across the sky
> towards where the lightning was. As soon as the fireball disappeared,
> lightning struck lighting the clouds and sky up in the distance.
>
>
> What Mr. Bennett may have seen was the rare occurrence of a "sprite" or a
> lightning event that travels from a positively charged thundercloud into the
> upper atmosphere (most storm clouds are negatively charged). It is
> currently conjectured that they are triggered by the passage of meteors in
> the proximity of a thundercloud. Evidence of this was presented by a
> British fellow (I think named Dr. Thomas) from a Utah University. He
> showed a video tape at the Leonid Mac conference dinner of a bright meteor
> passing behind clouds immediately followed by a vertical lightning discharge
> that actual traces is way up the meteor's track ! Pretty awesome video clip.
>
> Pete Gural
> peter.s.gural@cpmx.saic.com
> To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
> http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html
>
To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html
References: